The two patents, U.S. Pat. No. 6,182,767 and U.S. Pat. No. 6,371,212 as well as their references, form a background for the instant invention. The embodiments disclosed herein, for the instant improved drain nozzle, comprise a novel improved approach for the design of drain nozzles in general, improving on the capacity of a drain nozzle to bear weight and to shape and discharge foam.
Drain nozzles are structured to be stationed in trenches in the floor of a facility, covered by a grating. Thus the nozzle and grating system must be able to withstand any traffic of the area, such as an aircraft or other equipment rolling over or sitting upon the grating. Further, in the event of a body blocking portions of discharge from a drain nozzle and grating, adequate drainage should be provided such that the foam supply pressure at other nozzles on the foam supply line is not significantly impacted.
Other design requirements for drain nozzles vary with the facility to be protected. A drain nozzle to be used in an aircraft hangar, for instance, typically is subject to one requirement that the nozzle discharge foam a given distance, such as 20 feet, laterally for 360 degrees, without discharging the foam more than one or two feet in height. The purpose of this requirement is to avoid destroying or harming expensive equipment in the hangar with the foam.
The instant inventive design proposes to satisfy the above requirements in an improved manner.